why don't they make a hybrid diesel?

thomsbrain

Lifer
Dec 4, 2001
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Originally posted by: sdifox
ins't there a gas engine Benz is working on that behaves like Diesel?

I believe GM is working on one of these. It uses gasoline but can run without spark ignition in certain circumstances.

As for a hybrid diesel, there's no reason they can't do it (IIRC, there are some UPS or Fed-Ex trucks that have this now), but both diesels and hybrids add cost and weight to a car, and I think most manufacturers have decided that they couldn't sell an econocar with a $5000 powertrain option. So it's been one or the other so far, based on what they felt they could market more easily (hybrids for NA, diesels for Europe).
 

joutlaw

Golden Member
Feb 18, 2008
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I believe some UPS trucks use a combination of diesel/hydrualic hybrid. It was in a car and driver article a few months ago.
 

Fenixgoon

Lifer
Jun 30, 2003
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Originally posted by: sdifox
Ins't there a gas engine Benz is working on that behaves like Diesel?

http://www.gizmag.com/go/7679/

They are not the first ones to do it.

i know VW is working on a "true" gasoline version of a diesel engine - homogenous charge compression ignition (HCCI).

i believe GM is also looking into it.
 
Feb 10, 2000
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Diesels are already highly fuel-efficient. I doubt you could make a hybrid drivetrain/diesel combo even moderately cost-effective to the would-be buyer. As thomsbrain correctly observes, I don't think there's much of a market for a super-efficient, $30,000 Jetta TDI Hybrid.
 

angry hampster

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Dec 15, 2007
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www.lexaphoto.com
Originally posted by: Demon-Xanth
Diesels generally don't like to stop/start, they like to keep running. Hybrids do a lot of engine stop/starting.

This is what I was thinking. I realize that hybrids typically don't use a traditional starter mechanism, but a lot of start & stop on a diesel is asking for trouble./
 

crosshairs

Golden Member
Jan 25, 2007
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Dodge and Cummins are working on a hybrid Diesel/Electric truck engine, not sure if it will ever see production though.
 

Sukhoi

Elite Member
Dec 5, 1999
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BAE Systems already has a hybrid diesel powertrain for city buses. It apparently saves a ton of money on brake replacements and the associated downtime via the regenerative braking.
 

91TTZ

Lifer
Jan 31, 2005
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Personally I don't think the real benefit is in the batteries but instead in the ability to run the engine at a constant RPM where it is most efficient. I'd like to see a "budget" version of hybrids with an engine driving an electric motor with a large capacitor in between instead of a high capacity battery. The large capacitor would only help it accelerate off the line and could absorb some charge while braking but the car wouldn't need to drive for miles on the battery alone.

It seems like so much money is spent on batteries and that's really a waste. Eventually, all of the power is going to be generated by the fuel burning engine, so there isn't too much of a point having that much storage. It really only acts as a damper between the electricity being generated and the electricity being consumed.
 

Sukhoi

Elite Member
Dec 5, 1999
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Originally posted by: 91TTZ
Personally I don't think the real benefit is in the batteries but instead in the ability to run the engine at a constant RPM where it is most efficient. I'd like to see a "budget" version of hybrids with an engine driving an electric motor with a large capacitor in between instead of a high capacity battery. The large capacitor would only help it accelerate off the line and could absorb some charge while braking but the car wouldn't need to drive for miles on the battery alone.

It seems like so much money is spent on batteries and that's really a waste. Eventually, all of the power is going to be generated by the fuel burning engine, so there isn't too much of a point having that much storage. It really only acts as a damper between the electricity being generated and the electricity being consumed.

You're just talking about a series hybrid there. With a parallel hybrid the battery is used much more to supply power to systems while the power generation is turned off. But yes, a super capacitor in a series hybrid application would be interesting.